TeX:
\left\{ W\!\left(z\right) : z \in \mathbb{C} \setminus \mathbb{R} \right\} = \left\{ x + y i : y \in \left(-\pi, \pi\right) \setminus \left\{0\right\} \;\mathbin{\operatorname{and}}\; x \in \left(-y \cot(y), \infty\right) \right\}Definitions:
| Fungrim symbol | Notation | Short description | 
|---|---|---|
| LambertW | Lambert W-function | |
| CC | Complex numbers | |
| RR | Real numbers | |
| ConstI | Imaginary unit | |
| OpenInterval | Open interval | |
| Pi | The constant pi (3.14...) | |
| Infinity | Positive infinity | 
Source code for this entry:
Entry(ID("2d3356"),
    Formula(Equal(Set(LambertW(z), ForElement(z, SetMinus(CC, RR))), Set(Add(x, Mul(y, ConstI)), For(Tuple(x, y)), And(Element(y, SetMinus(OpenInterval(Neg(Pi), Pi), Set(0))), Element(x, OpenInterval(Mul(Neg(y), Cot(y)), Infinity)))))))